Pick up trucks have become a mainstay in the automotive market for agricultural, commercial, landscaping and other uses. Generally, these pick up trucks are used for loading and hauling, but sometimes it is easier to dump the load out of a pick up truck than it would be to unload the cargo box of the pick up. However, dump trucks are usually large heavy-duty trucks with heavy-duty hydraulics systems for lifting the relatively heavy metal truck box beds. The lifting and tipping systems not only have to lift the truck box itself but it must also lift the contents of the box as well.
In order to increase fleet mileage and better comply with environmental standards, the automotive industry has been trying to reduce the weight of their vehicles. They have been increasingly looking at resin plastic pick-up boxes, as they are sometimes lighter in weight than a traditional steel metal pick-up truck boxes. One type of pick-up truck box made of plastic is made by a powder molding technology owned by 3DM Technologies, Inc., of Troy, Mich. The pick-up truck box made by their process is approximately 100 pounds less than a standard metal pick-up truck box, lending itself to a much simpler method and mechanism for affecting a dump truck tipping mechanism. By powder molding the truck box itself, stanchion supports and other metallic inserts can be molded directly into the pick-up truck box, acting as connecting and attachment points for the hydraulic dumping mechanism.
It is an aspect of the present invention to utilize the reduced weight and singular component truck box bed created by the use of plastic forming technology for making a light weight, one piece plastic body, and especially a plastic truck box bed that can be easily lifted, The PCT International Patent Application Serial No. PCT/US02/03298 for the invention entitled “Processes For Forming Plastic, Apparatuses For Forming Plastic, And Articles Made Therefrom”, also owned by the present owners of this application, is incorporated herein by reference. U.S. Provisional Patent Application No. 60/414,969 is also incorporated herein by reference.
Therefore, it is an aspect of the present invention to provide a lightweight plastic pick up truck box for use on street grade, light-duty pick-up trucks. It is another aspect of the present invention to provide a plastic pick up truck box with a light duty dumping mechanism. This is especially desirable for providing a lightweight dumping pick up truck without having the need to purchase a special heavy-duty truck. Also, as the truck box is made by various plastic forming technologies, such as the powder molding technology described above, the weight of the box should be less than the conventional truck boxes, and a light duty dumping mechanism can be utilized.
Because the payload capacity may be increased due to less weight, this makes the dump truck tipping mechanism more desirable. The present invention provides these aspects and advantages and also provides a tailgate construction which can reach down to the ground such that a normal size light-duty pick-up truck can be utilized for running various tools and equipment directly up the tailgate into the bed of the truck, allowing the easy loading of wheeled vehicles, such as heavy duty wheelchairs, recreational vehicles such as ATVs and motorcycles, as well as the loading of small livestock, including dogs and the like.